The present invention relates to devices for making marks in metal parts and other objects.
For identification purposes, most manufactured parts are provided with some sort of identifying indicia stamped or marked thereon. For example, parts may be given a catalog number, a size number, a routing number, or a source identifier. To do so, the parts are first machined or otherwise manufactured, and then taken to a separate, dedicated machine for stamping or marking. This creates one or more additional steps in the manufacturing process, increasing the costs involved, not to mention the additional expense of the dedicated stamping machines themselves. Additionally, the stamp or punch in the stamping machine may need to be manually changed over each time a different identification indicia is required, further adding to manufacturing and labor costs.
Also, in many instances it may be necessary to provide a part with some sort of identifying indicia during the manufacturing process itself, before the part is finally finished. For example, if a common manufacturing line handles several different parts, indicia may be needed to properly sort the parts further down the line. Taking the parts off the line for stamping at a remote stamping machine is impracticable, if not impossible, and adding dedicated stamping machines on the manufacturing line increases both required capital outlay and manufacturing time.
Accordingly, a primary object of the present invention is to provide a marking device, meant for use with a general purpose machining center or other machine tool, that can mark and identify a machined part before the part is taken out of the machining center.
Another object of the present invention is to provide a marking device that eliminates the need to stamp or otherwise mark a machined part at a location removed from the machining center or manufacturing line.
Still another object of the present invention is to provide a marking device that can provide any number of marking indicia patterns.
A spindle mounted marking device, for use with CNC machines or other manufacturing or machining tools, is disclosed for marking and identifying machined parts. In a preferred embodiment, the marking device comprises a stationary, hollow, tubular body capped at either end with top and bottom plates. A main shaft extends down through the top plate along the central axis of the body, and is rotatably held in place by upper and lower bearings. A cylindrical cam having one or more cam lobes disposed on an underside thereof is attached to the main shaft within the body such that the cam rotates when the main shaft rotates. A spring-biased marking stylus slidably extends through a guide attached to the bottom plate, such that an upper, anvil portion of the stylus tracks along an underside of the cam, and a lower, marking tip portion of the stylus lies just within the guide.
For marking a part, the marking device""s main shaft is operably connected to a machining center spindle. The machining center is controlled to position the guide just over the part to be marked, and to start the machine""s spindle rotating. This in turn causes the main shaft and the cam to rotate. As the cam rotates, with the body remaining stationary, the cam lobe contacts the anvil portion of the stylus, forcing the stylus axially downwards through the guide and the marking tip against the part. Once the cam lobe passes the anvil, the stylus springs back into place against the underside of the cam until the cam lobe next comes around.
To create a complex pattern, the machining center moves the part and/or marking device, according to the particular pattern desired, as the stylus is periodically forced axially downwards, i.e., as it reciprocates. More specifically, the spindle is set to rotate at a constant rate. Given the number of cam lobes and the spindle""s speed, the machine knows the number of stylus extensions per minute, and the time there between. This allows the machining center to appropriately time the movement of the part and/or the marking device to produce the desired indicia pattern.